水环境重金属的光学与LAPS传感器检测方法及仪器的研究

发布时间：2018-05-13 03:25

本文选题：水环境重金属检测 + 分光光度法　；参考：《浙江大学》2017年硕士论文

【摘要】：由于近几年我国经济的粗犷式发展,导致了水环境重金属污染严重。重金属污染不仅对人体健康造成很大影响,而且会对生态环境造成严重破坏。因此国家越来越重视对重金属的检测。虽然现在有很多成熟的方法可用于重金属的检测,但是这些方法一般具有仪器体积庞大,检测时间长,检测成本高等缺点而不适用于重金属的现场检测。本文研究了基于分光光度法和光寻址电位传感器(Light Addressable Potentiometric Sensor,LAPS)实现重金属检测的方法。本文首先介绍了水环境重金属的污染现状和几种主要的重金属检测方法以及LAPS传感器的发展和应用,然后设计了基于分光光度法自动化铜离子检测仪器,基于LAPS小型化分析仪器和多通道LAPS检测系统,最后探索了基于LAPS检测系统的H+扩散图像检测方法。本文的主要工作和创新点包括如下几个方面:1.设计了基于分光光度法对铜离子的自动化检测仪器。本文研究了基于分光光度法的水环境中的Cu2+检测方法,利用晶体管控制蠕动泵的开启和关闭,并利用光电传感器完成液滴检测,实现了仪器自动化进样。结合可自动调节光强的光学检测系统,实现了自动化检测仪器样机设计。分析了仪器的进样系统和最佳测试条件,得到较好的Cu2+线性曲线,并与标准的分光光度计仪器进行比对,结果表明,本仪器完成了对溶液的精确进样,实现了对Cu2+的自动化检测,Cu2+的检出限为6μg/L,低于标准仪器的检出限。2.设计了基于LAPS传感器的小型分析仪器,实现了重金属的检测.本文采用了基于AD630芯片的同步检波电路,实现方波乘法器对被测信号的解调,从而降低了一般模拟乘法电路产生的直流漂移。并设计了时间常数为300ms,衰减率为12dB/oct的低通滤波器,实现了锁相放大。设计了 LED激发光源及其信号发生电路,编写了分析和控制软件,完成了基于LAPS的小型分析仪器。通过在LAPS表面固定Cu2+敏感膜,实现了对Cu2+的检测。实验结果表明该仪器具有检测重金属的功能和小型方便的特点。3.设计了多通道的LAPS检测系统,结合软件完成双相位锁相放大算法,实现了多参数检测。本文设计了基于数据采集卡USB-6211的多通道LAPS检测系统,包括多路光源激发不同LAPS传感器和软件实现双相位锁相放大算法,实现同时检测多种参数的功能。软件锁相放大算法中采用巴特沃斯滤波器作为前置带通滤波器,结合正弦信号乘法和椭圆低通滤波器实现双相位锁相放大,并对结果求平均值,从而提高了系统信噪比。该系统实现了对Pb2+和H+的同时检测。实验结果表明,软件实现的锁相放大算法很好的完成了对多通道LAPS信号的检测,实现了基于LAPS的多参数检测。4.探索了基于LAPS检测系统的H+扩散图像检测方法。研制了基于MAC6000的X-Y扫描控制器结合LAPS的H+动态扩散图像检测系统,开发了该系统的扫描控制软件和分析算法。通过在LAPS上固定琼脂基质,扫描其中的H+扩散图像,从而实现了 H+扩散过程的动态检测。
[Abstract]:Because of the rugged development of our country's economy in recent years, heavy metal pollution in water environment is serious. Heavy metal pollution not only has a great impact on human health, but also causes serious damage to the ecological environment. Therefore, the country pays more and more attention to the detection of heavy metals. Although there are many mature methods now available for heavy metal detection, However, these methods generally have large volume, long detection time and high detection cost, which are not suitable for field detection of heavy metals. In this paper, the methods of heavy metal detection based on spectrophotometric method and Light Addressable Potentiometric Sensor (LAPS) are studied. The water environment is introduced in this paper. The pollution status of heavy metals and several major heavy metal detection methods and the development and application of LAPS sensors, and then design an automatic copper ion detection instrument based on spectrophotometric method, based on LAPS miniaturized analysis instrument and multi-channel LAPS detection system, and finally explore the H+ diffusion image detection method based on LAPS detection system. The main work and innovation of this paper include the following aspects: 1. the automatic detection instrument for copper ion based on spectrophotometric method is designed. In this paper, the Cu2+ detection method in water environment based on spectrophotometric method is studied. Using transistors to control the opening and closing of the peristaltic pump, and using the photoelectric sensor to complete the liquid drop detection, the instrument is realized. The automatic testing system of the light intensity is combined with the automatic adjustment of the optical intensity. The design of the automatic testing instrument is realized. The sampling system and the best test conditions are analyzed. The better Cu2+ linear curve is obtained and compared with the standard spectrophotometer. The result shows that the instrument has completed the accurate sampling of the solution. The automatic detection of Cu2+ is realized. The detection limit of Cu2+ is 6 u g/L, and the detection limit of the standard instrument is lower than the detection limit of standard instrument. A small analytical instrument based on LAPS sensor is designed to realize the detection of heavy metals. This paper uses a synchronous demodulation circuit based on AD630 chip to realize the demodulation of the measured signal by the square wave multiplier, thus reducing the general mode. The DC drift produced by the quasi multiplicative circuit is designed. A low pass filter with a time constant of 300ms and a attenuation rate of 12dB/oct is designed to realize the phase lock amplification. The LED excitation source and its signal generator are designed. The analysis and control software is written and a small analytical instrument based on the LAPS is completed. A Cu2+ sensitive film is fixed on the LAPS surface, and the realization of a Cu2+ sensitive film is realized. The test results show that the instrument has the function of detecting heavy metals and the features of small convenience..3. has designed a multi-channel LAPS detection system, and the dual phase phase locked amplification algorithm is completed with the software to realize the multi parameter detection. This paper designs a multi-channel LAPS detection system based on the data acquisition card USB-6211, including multiple channels, including multichannel LAPS. The light source excites the different LAPS sensors and software to realize the dual phase phase locked amplification algorithm to realize the function of simultaneous detection of various parameters. In the software phase locked amplification algorithm, Butterworth filter is used as a pre band pass filter, the dual phase phase locked amplification is realized with the sine signal multiplication and the elliptical low pass filter, and the results are calculated. Thus the system signal-to-noise ratio is improved. The system realizes the simultaneous detection of Pb2+ and H+. The experimental results show that the software implementation of the phase-locked amplification algorithm completes the detection of multichannel LAPS signals well, realizes the multi parameter detection based on LAPS, and explores the H+ diffusion image detection method based on LAPS detection system, and develops the MAC6 based on MAC6. 000 X-Y scanning controller combines LAPS's H+ dynamic diffusion image detection system, and develops the scanning control software and analysis algorithm of the system. By fixing the agar matrix on the LAPS, the H+ diffusion image is scanned, thus the dynamic detection of the H+ diffusion process is realized.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212

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